Smoothing/Relaxation battery tests

This end of the year /new year will be full of surprises and good news … I hope that. 😉

Regarding Unlimited clay I have very good news and also a new development surprise in the particles simulation field … but sorry, you will have to wait a bit more for that ;), as I have a very low bandwith and in order to upload a new video I have to do wonders to shrink and split it in dozens of parts and send it by email to my friend Lapinou  … so new videos are staking here 😦 (lapinou’s note: finally uploaded!)

It’s now the turn of the test smoothing/relaxation algorithm I have been developing last week:

Three smoothing/relaxation algorithms are currently implemented in Blender (not counting the subdivision surfaces because it changes topology but the output of that algorithm is also a smooth surface) the smooth vertex editmesh tool, the relax addon and the UV Minimize stretch tool. I want to point out that there´s not the ideal relaxation algorithm valid
for every object: every relaxation scheme has advantages and drawbacks over others and are more or less suited for the task.

The smooth vert algorithm is an all around average solution, it performs a laplacian relaxation in the field and while is a very stable method it suffers from an excessive shrinkage effects of the shapes. The relax addon tries to solve the shrinkage issue and is very good on that, but it’s somehow slower since it’s based on shrinkwrap and laplacian smoothing.

The UV minimize stretch tool performs a different relaxation: it’s based on smoothing angles, not edges, and while it’s very useful for many cases, it’s not valid for others (see my test video).

Currently I have implemented four algorithms more (eventually I will only stay with two of them only)

1) edge – spring relaxation: it acts push/pulling verts of the mesh based on elastic forces , very good on retaining original shape much with no shrinkage, is very similar to other cases but have some ill outputs.

2) revised ideal length relaxation: this is very similar to the spring relaxation and acts in a similar fashion, without many of the ill cases that affect the former.

3) revised laplacian relaxation: this one, based on the original laplacian, is also an all around good average solution but with zero shrinkage and much more faster/cheaper than the relaxation addon since it doesn´t perform shrinkwrap evaluations.

4) HC – relaxation: taken from the paper “Improved Laplacian Smoothing of Noisy Surface Meshes” this one again is based on the laplacian relaxation with a shrinkage component but very small and needed in the reconstruction cases, this algorithm is very good on smoothing and shape retaining at the same time.

All the previous algorithms have boundary/open mesh detections to avoid shape deformation but again that is an optional user feature. In general, every smoothing algorithm perform a tradeoff between smoothing and shape retention: the more the shape is maintained the less it is smoothed and vice versa, the first three are aimed to shape retention, while the fourth is aimed in the middle, to retain shape and to smooth at the same time.

I have made a new video test, this time with a wider battery tests and all the smoothing algoritms, since I haven´t implemented yet for UV I replicate a mesh with a Suzanne´s UV to get an idea of how it may work. Please be a little patient since this may take me very long to upload.

All the best

Smoothing/Relaxation battery tests

11 thoughts on “Smoothing/Relaxation battery tests

  1. Moolah says:

    Yeah, amazing results! Anyway – almost all compex sculpted models usually will need some retopo-work in cases to use with bones&rigs.
    Happy New Year! 🙂


    1. You’re one of the most talented Blender developer! Tell us, what are your plans for 2011? What will you focus on? Particles, Sculpting, Procedural Textures or something else?


  2. Thanks for your work on this Farsthary. Very smooth looking! 😛

    Can’t wait to see what tricks you have planned for the new year. I’m wondering though if there isn’t an easier way to share your creations… Are you uploading these to your branch of Blender? If that’s the case someone over here could compile your branch and then you could just email a .blend file for rendering with a text file (even a .srt subtitle file) to add the comments over the top…

    Anyway, it’s great to see all of the work that’s gone into this, and also to see experimenting around with UV smoothing too. That’s something that will definitely come in handy!

    Su amigo
    Blendiac 🙂


    1. farsthary says:

      Hi my friend 🙂

      Hopefully I have tons of new plans 🙂 sadly currently I´m not uploading to my branch , is terribly outdated so I don´t base my code on that, I would like to clean it up and start over a fresh branch but that will need a bandwith I currently don´t have … hope this year brings me new possibilities 😉


  3. once again awesome,
    this time thanks to you and of course thanks to lapinou for helping you

    cheer up guy keep going you make blender so much better
    I can’t wait for the unlimited clay btw


  4. FreeMind says:

    Few ideas:
    Surface relax should preserve UV’s, so the texture wouldn’t change.
    Maybe even implent a tool out of that “Manual vertex grab along surface”, which would also preserve UV’s.

    Just sayin.


  5. blenderificus says:

    another great showcase of your smoothing features! I hope this makes it into trunk :-)!
    cant wait for more unlimited clay updates too. Thank you for your hard work.


  6. Peter says:

    The revised laplacian relaxation looks best for me, because it retains the volume greater than the other algorithms! the second is HC relaxation! just sharing my opinion, but i will be glad to see these on the finals!


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